Tank level indicator



E. C. JACOBSONv TANK LEVEL INDICATOR Filed Nov. 2. 1931 INVENTOR.

' BY 3- 762A man im A TTORNEYS,

Patented Mar. zo, 1934 UNITED STATES' PATENT OFFICE Huron Portland Cement Company,

Detroit,

Mich., a corporation of Michigan Application November 2, 1931,'serial No. 572,634

3 Claims.

This invention relates to a tank level indicator and has to do particularly with a device for giving a warning when the material in the tank reaches a predetermined level.

In use, this device may be connected to many sorts of tanks or bins, for example, the bins of a ready-mixed concrete plant. Movement of the diaphragm, which is positioned in one of the walls of the pin, effects the operation of a mercury switch of the ordinary sort. This switch may be so connected that its actuation by the diaphragm will operate an electric bell or light. The

switch may also be connected to cause an electric motor to start or Stop.

The principal advantage `of this invention is the simplicity of its operation and design and the multiplicity of uses to which it may be adapted. A further advantage lies in the fact that the device may be adjusted to operate at different pressures.

In the drawing:

Figure 1 is an elevation of the device connected to a tank.

Figure 2 is a view along the line 2-2 of Figure 1.

Figure 3 is a view along the line 3-3 of Figure 2. .i

Figure@ is a view along the line 4-4 of Figure 2.

Referring to the drawing, 1 represents the wall of a tank to which the device has been connected, and 2 a circular hole in the wall. The supporting ring 3 which is preferably an iron casting is formed with two outwardly extending parallel flanges 4 and 5 and an interior flange 6. The ring is secured to the tankl by bolts 7 which pass through the flange 5 and the wall of the tank. The cover 8, which may be a stamping, iscylindrical in forml and. has a flangeI 9 which corresponds in size to the ange 4. The cover is xed to the supporting ring, the gasket -10 being rst inserted between these two members, by bolts 11 passing through the two flanges.

The stud 12, threaded through approximately one-half of its length, is inserted in the hole 13 in the upper portion of the flange 6 and isxed to the flange by means of the nuts 14 and 15. At the other end of the stud is a longitudinal slot 16, positioned vertically and approximately half the length. of the stud. The lever 17 is a flat bar preferably of steel having ends which are bent parallel to each other at an angle of about 75 with the main portion of the lever, forming the arms 13 and 19. As shown in Figure 1, the lever is pivotally secured within the slot 16 by the bolt (Cl. 20o-85) 20. The counter-weight 21, which may be of lead,

is suspended from the arm 18 by means of a hook 22 which is bolted to the counter-weight. The upper end of the hook passes through a longitudinal slot 23 in the upper arm. Nuts 24 and 25 60 when tightened, permit the hook to be held in any desired position throughout the length of this slot, thereby varying the force exerted by the counter-weight. A further variation might be obtained by placing washers on the top of the counter-weight. The mercury switch 26, having terminals 27 and 28, is secured to the lower arm.

The stud 29 has at one end a slot 30 corresponding in shape to the slot 16 of the other stud. The lever 17 is pivotally mounted within the slot 30 70 by means of the bolt 31. The stud has at its other end a threaded portion to receive the nuts 32 and 33 which are adapted to hold in place the discs 34 and 35 which form the center of the diaphragm 36. The diaphragm consists of a circular piece. 37 of flexible material such as canvas, leather or rubber, havingA its center portion reinforced by the discs 34 and 35 which are riveted together. The flexible portion is securely held at its periphery between the iiange 5 and the ring 30 38 as shown in Figure 4. The bolts 39 fix the ring to the flange. The gasket 40 is positioned between the ring 38 and the wall of the tank.

The normal position of the indicator, that is, when the level of the material 'in the tank is 35 below the diaphragm, is shown in Figure 1. The downward pressure of the counter-Weight 21 tends to force the stud 29 in an vaxial direction toward the interior of the tank," thereby holding the diaphragm taut. When the tank is filled to the level of the diaphragm, a pressure will be exerted against the latter. There will be a resulting movement of the diaphragm and the stud 29 when the total pressure exerted upon the diaphragm is greater than the counteracting force exerted by the counter-weight. When the force exerted upon the diaphragm is sufficient to press the lower part of the lever 17 inward tosuch an extent as to raise the lower arm 19 to a position approximately horizontal, the mercury in Athe switch 26 will complete the circuit, which will cause the warning signal to operate. Conduits from the contacts 27 and 28 may be led off through the hole 41 in the support ring.

1 recognize that diaphragms and springs have i105 been used in connection with indicating devices but their use has been somewhat unreliable and not altogether satisfactory. My present combination makes possible the entire elimination of springs by the use of a proper lever arrangement,

utilizing gravity to return the diaphragm to its inward position, and at the same time using the lever system to control an electric circuit. By using a mercury vapor switch on oneend of the lever controlled by the diaphragm it is possible to eliminate the troublesome contact switches which are generally used with spring controlled diaphragms. Furthermore, the whole control apparatus is thus embodied in a single unit carried on a single lever which may be easily removed for repair or substitution.

It may be seen, therefore, from the foregoing description, that this device is simple in design and operation. It may be used, furthermore, in the circuit of an electric light or bell as a warning, or of an electric motor to effect automatic control of the level of the material in the tank.

What I claim is:

1. A level indicating device comprising in combination a diaphragm, a lever pivoted to swing about a horizontal axis having a depending portion, a counter-weight mounted on one end of the lever and a mercury switch on the depending portion of the lever and below the counter-weight, means operatively connecting the diaphragm with the lever whereby the weight normally holds the diaphragm distended, the diaphragm being on one side of the pivot and the said counterweight and switch being onv the other side of the pivot.

2. A level indicator comprising in combination of a support, a diaphragm mounted on one side of the support, and a lever mounted on the other side of the support and having a depending portion, means operatively connecting the diaphragm to the lever, a weight mounted on one end of the lever for normally holding the diaphragm distended, and a mercury switch mounted on the depending portion of the lever and below the counter-weight whereby pressure exerted against the diaphragm sufficient to overcome the counter-weight causes the lever to pivot and the mercury switch to close.

3. A level indicator comprising in combination a support, a diaphragm positioned on one side of the support and a lever pivotally mounted on the other side of the support, the said lever being U-shaped with a pair of parallel arms and pivotally mounted to swing about a horizontal axis, means pivotally connected to the lever between the said arms for operatively connecting the lever to the diaphragm, a counter-Weight secured to the upper arm for normally maintaining the diaphragm distended, and a mercury switch mounted on the lower arm whereby pressure on the diaphragm overcoming the counter-weight pivots the lever to throw the mercury switch.

ELMER C. JACOBSON. 

